Process of manufacturing alkali hydroxids.



ABVIED W. EKSTROM,

PBQGESS OE MANUFACTURING ALKA as, ft o 0F LOS A.-TGELES,

CALIFORNIA.

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To all whom it may concern:

Be it known that I, Arvin Vt. Ens'rnoar, a citizen of Sweden, residing at Los Arr geles, in the county of Los Angeles and State'of California, have invented new and useful Improvements in Processes of ManufacturingAlkali Hydroxide, of which the following is a specification.

This invention relates to a process for producing alkali hydroxids from the native alkali salts by purely chemical action, and it is the chief object of the invention, to accomplish the production of alkali hydroxids by treating the alkali salts by means of barium oXid or hydroxid and hydrofluosilicic acid. v

In order to illustrate the manner of carrying out the process the method, as applied to the manufacturing of sodium hydroxid (NaOI-l) from native sodium salts such as chlorids has been given as an example. The steps of the process will now be set forth in order:

11. Preparation of sodium fluosilicata- An aqueous solution of sodium chlorid (NaCl) is treated in a suitable vessel with hydrofluosilicic acid whereby sodium fluosilicate, tila SiF is precipitated leaving tbrhydrochloric acid in solution. The react.on that takes place is as follows:

ZNaCl +H SiF,=Na Sili 21101. (Pzecipitate) (Solution) The liquid obtained from the precipitate in this reaction, namely hydrochloric acid can be easily separated from the precipitate by dccantation and can be concentrated and applied to any, of the common uses of this chemical.

B. Treatment of sodium flaosilz'cate with barium hydrowirZ.-The precipitate of sodium t1uosilicate is treated by boiling in a suitable vessel with an aqueous s0lution of barium hydroxid whereby a double decomposition takes place, yielding sodium hydroxid and a precipitate of barium liu: osilicate, in accordance with the following chemical equation (Solution) (Preclpitate) The sodium hydroxid or caustic soda thus obtained in solution may be readily decanted from the precipitate and can then be conveyed into any suitable evaporator. for concentration.

Specification of Letters Patent. Application filed April 17, 1911. Serial No. 621,504.

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C. Recoocry 0f hydrofl'aoslicic acid-e The precipitate of barium fluosilicate is treated by slightly heating in a suitable iron vessel with diluted sulfuric acid (H 80 whereby the barium fluosilicate is decomposed forming hydrofluosilicic acid, (H SiF which goes into solution, and an insoluble precipitate of barium sulfate (BaSOQ. The reaction that takes place is as follows:

H SO +BaSiF SiF E- B3180 (Solution) (Prccipitnte) The aqueous solution of hydrofiuosilicic acid, thus obtained, is separated from the precipitate by decantation and may then be used again in carrying out the stepof the process described under A. In this manner the said hydrofluosilicic acid is savedand may be used over and over again with very The barium sulfate (BaSOQ thus obtained as a precipitate may be con verted into barium hydroxid (Ba(OH) by treating the same with oil as a reducing agent in the presence of heat as described in my application, SIN. M2279, tiled August 7, 1911 for a patent for a process of manufacturing barium and strontium com: pounds. By this process barium sulfid (:BaS) is formed which is to be treated with carbonic acid (CO2) conyerting it into barium carbonate (B2100 and this barium carbonate is converted into barium oxid (BaO) by the use of oil as a reducing agentin the presence of heat, as set forth in my component application. The barium oxid thus obtained is hydrated with water conerting it into barium hydroxid or the latter substance being useful .again in stage B of the above described process. v

What I claim is 1-- The process of making alkali hydroxid comprising the treating of an alkali fluosilicate with barium hydrozgid whereby alkali hydroxid and barium fiuosilicate are formed.

In witness that I claim the foregoing I have hereunto subscribed my name this 11th day of April, 1911.

ARVID N. EKSTROM.

lNitnesses EDMUND A. STRAUSE, EARLE R. PoLLAm). 

